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Volume 46 (1992)
- Issue 6 Pages 359-
- Issue 5 Pages 293-
- Issue 4 Pages 212-
- Issue 3 Pages 135-
- Issue 2 Pages 71-
- Issue 1 Pages 3-
Volume 46, Issue 3
Displaying 1-5 of 5 articles from this issue
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Ren KUWABARA, Aritsune SAEKI, Shin-ichi NAKAJIMA1992 Volume 46 Issue 3 Pages 135-149
Published: 1992
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSThe water quality, the scale of the aquarium system and some relating factors were investigated on commercial aquariums equipped with closed-circulating system. The data were analyzed mainly for the discussion of nitrate accumulation caused by fish metabolism and excretion, N/P ratio and others, in comparison with natural waters. Meanwhile, the purifying activity of the filter sand was estimated on the basis of the balanced-aquarium theory by SAEKI and his fish culture experiments.
By using these results, the methods of calculating the amount of sand filter which corresponds to the amount of fish, the amount of supplying water required to prevent nitrate accumulation, and the rate of aeration to total oxygen consumption of cultured fishes were compositively calculated.
From these analyses, the necessary basic standard for planning the installation of an aquarium was determined.View full abstractDownload PDF (10429K) -
Change of Chemical Composition in Mother Liquor on Surface of Common Salt on Drying (Part 1)Yasushi NIINO, Hitomi NISHIMURA, Masatoshi ARITA1992 Volume 46 Issue 3 Pages 150-157
Published: 1992
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSWe identified the hydrates formed from mother liquor on surface of salt on drying, measured the transition temperatures of those hydrates, and investigated the drying temperature condition for measuring of loss of mass on drying of salt.
The results were as follows:
1) For salt manufactured by the ion-exchange membrane method, the hydrates of carnallite (KMgCl3·6H2O), tachyhydrite (CaMg2Cl6·12H2O) and bischofite (MgCl2·6H2O) were formed from the mother liquor on the surface of common salt on drying, and these affected the measurement of loss of mass on drying. For solar salt, carnallite, bischofite and gypsum (CaSO4·2H2O) affected this measurement.
2) The transition temperatures of carnallite were about 95°C and about 145°C. Tachyhydrite was about 135°C, bischofite, about 110°C and 160°C, and gypsum (CaSO4·2H2O), about 105°C.
3) 110°C prescribed by ISO 2483 was near the transition temperatures of bischofite and gypsum. 140°C prescribed by “Methods for salt analysis” in Japan was near that of carnallite and tachyhydrite.
4) The loss of mass by the transition of tachyhydrite at about 135°C and that by thermal decomposition of bischofite were factors causing differences between the loss of mass at 110°C and at 140°C.
5) In the range of 120°C to 130°C, there was no transition temperature of these hydrates, so temperatures in this range were considered to be a suitable temperature condition for measuring loss of mass on drying.View full abstractDownload PDF (5493K) -
Karoku SAKAMOTO, Masutoshi SHIOTA1992 Volume 46 Issue 3 Pages 158-170
Published: 1992
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSWe are investigating the method of manufacturing potassium carbonate from Engel salt by means of heat decomposition. The outline of this method of manufacturing fairly resembles the Engel-precht method. The chemical fundamental equation of Engel-precht method is as follows:
1. 2KCl+3 (MgCO3·4H2O) +CO2=2KHCO3·4H2O+MgCl2.
2. 2 (KHCO3·MgCO3·4H2O) =K2CO3+2MgCO3·9H2O+CO2.
This well-known classical Enge1-precht method has been renovated and modified so as to be suitable and adoptable in a bittern factory. The points of innovation over the Engel-precht method are:
To use magnesium hydroxide, and to use the concentrated gas of CO2 in place of waste dilute combustion gas.
The first step of the experiment is the design of the equilibrium diagram on oceanic salts.
In order to make, Na, K2, Mg, Cl2, HCO3, each compartment change freely and perfectly, on condition in pretence of CO2 gas, the author felt it necessary to make use of the diagram of ternary prism system. The author has drawn diagrams on ternary prism system. By way of graphical calculation, the distribution of the amount of materials, the yield of potassium, and the water equivalent have been determined. The next step of the experiment is the beaker test using the pure liquid CO2 and magnesium hydroxide in potassium chloride solution. The data aquired in the laboratory has been applied to the actual production process on the same scale by using waste combustion gas.
The last step of the experiment is intermediate industrial experiment. This experiment of manufacturing Engel salt has been the most important aim of the whole attempt of the investigation.
The chemical composition of Engel salt and yield of potassium carbonate are as follows:
Engel salt% K Mg Cl SO4 K yield
15.8 9.5 1.4 0.03 48.3
potassium carbonate %
K2CO3 KCl KHCO3 K2O K yield % from Engel salt
86.5 0.1 2.2 60.0 75.0
The result of the experiment has been nearly satisfactory.View full abstractDownload PDF (7171K) -
Hitomi NISHIMURA, Masatoshi ARITA, Yasushi NIINO1992 Volume 46 Issue 3 Pages 171-174
Published: 1992
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSWe investigated the applicability of the method that uses enzyme reagents for the measurement of magnesium in salt and brine.
The results were as follows:
1)Thecalibration curve of magnesium was linear until 100mg/l.
2) The measurement times took 3 minutes.
3) The amounts of sodium chloride of 100-1,000 times that of magnesium did not affect the measurement of magnesium. Also, that of calcium of 1-8 times and potassium of 2-10 times did not affect this measurement.
4) The fluctuation coefficient of ten repeated analyses was about 2%.
5) The determination value by the enzyme reagent method agreed well with that by chelatometric titration method.
Thus, we confirmed that the enzyme reagent method could be used for the measurement of magnesium in salt and brine.View full abstractDownload PDF (3294K) -
Dennis S. KOSTICK1992 Volume 46 Issue 3 Pages 175-198
Published: 1992
Released on J-STAGE: February 19, 2013
JOURNAL FREE ACCESSDownload PDF (16233K)
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